Tag: postgresql

Waiting for 9.2 – cascading streaming replication

On 19th of July, Simon Riggs committed patch:

Cascading replication feature for streaming log-based replication.
Standby servers can now have WALSender processes, which can work with
either WALReceiver or archive_commands to pass data. Fully updated
docs, including new conceptual terms of sending server, upstream and
downstream servers. WALSenders terminated when promote to master.
 
Fujii Masao, review, rework and doc rewrite by Simon Riggs

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Waiting for 9.2 – Stacked Diagnostics in PL/pgSQL

On 18th of July, Tom Lane committed patch:

Add GET STACKED DIAGNOSTICS plpgsql command to retrieve exception info.
 
This is more SQL-spec-compliant, more easily extensible, and better
performing than the old method of inventing special variables.
 
Pavel Stehule, reviewed by Shigeru Hanada and David Wheeler

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Waiting for 9.2 – Avoiding reindexing on alter type of indexed column

On 18th of July, Robert Haas committed patch:

Avoid index rebuild for no-rewrite ALTER TABLE .. ALTER TYPE.
 
Noah Misch.  Review and minor cosmetic changes by me.

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Write Ahead Log + Understanding postgresql.conf: checkpoint_segments, checkpoint_timeout, checkpoint_warning

While there are some docs on it, I decided to write about it, in perhaps more accessible language – not as a developer, but as PostgreSQL user.

Some parts (quite large parts) were described in one of my earlier posts, but I'll try to concentrate on WAL itself, and show a bit more in here.

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explain.depesz.com update

Just updated explain.depesz.com site with new functionality – when showing parsed plan, there is new tab “stats". In there you can see some basic statistics of the query, used types of nodes, and tables that were used by it.

There are probably some problems with stats (it's new functionality, so bugs are imminent), but

As usual, some stats need to be added 🙂

  • Total count of plans in database: 18127
  • Count of private (not listed on history page) plans: 6965
  • Count of anonymized plans: 166 (this feature proved to be much less used than I thought it will be)
  • Since (including) May 2011, there are more private plans added than public ones. In June – 58.9% of all plans were private.

Waiting for 9.2 – relative paths in psql

On 6th of July, Robert Haas committed patch:

Add \ir command to psql.
 
\ir is short for "include relative"; when used from a script, the
supplied pathname will be interpreted relative to the input file,
rather than to the current working directory.
 
Gurjeet Singh, reviewed by Josh Kupershmidt, with substantial further
cleanup by me.

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